VIDEO: The Tandem . . . . HeliGraphix Multi-copter taking flight

Two T-Rex 450 remote-control helicopters are strapped to a special kind of board and controlled by 2 pilots. This Tandem works a bit like a multi-copter: The aileron function is realized by different blade pitch angles of the two helis while yaw is achieved by applying different elevator inputs. The pilots therefore need to act as a perfect team with to-the-point communication. The one thing which made this experiment quite challenging was the simple fact that such a construction had never been piloted before and no-one knew what flying it was like. The other thing is of technical nature: Unlike with multi-copters the rotors of both helis turn in the same direction. This is why the whole construction had a natural tendency to pirouette; in the beginning this caught us a bit by surprise but we managed to control it later on.